Mouse models of cancer have proven to be highly effective pre-clinical models for testing new cancer therapies for safety and efficacy. However, the generation of the most applicable mouse models of cancer is costly, time-consuming, and therefore not widely implemented. Generating new mouse models of cancer utilizing recently developed cutting-edge technologies will produce superior models in a more affordable and rapid fashion allowing new therapies to reach the clinic in a timely manner. To this end, we will optimize and implement a newly developed technology termed the CRISPR system. This system allows researchers to specifically delete or modify multiple portions of the mouse genome at one time in specific cells to induce tumor development. This model of cancer development as a pre- clinical testing platform is superior to current models as it is more rapid, cost effective, and easy to use. This will allow pre-clinical testing in accurate mouse models of cancer to be performed by many labs that do not have the resources to utilize the current mouse models, due to the aforementioned drawbacks. We propose to use the CRISPR system to generate new models of rapid onset osteosarcoma and pancreatic cancer, devastating diseases that affect pediatric and adult patients, respectively. All of the advantages of the CRISPR based models over traditional models will certainly attract many research labs to capitalize on the technologies potential in the field of cancer research and other diseases.